HP Linux Server Management Software - Manual (Page 42)

Toolkit utilities 42
• Auto is the default setting for new configurations. In this case, the storage system automatically selects
the I/O path from the redundant controller to the logical drive and dynamically load balances all paths.
• Manual enables you to assign the logical drive to a specific redundant controller. If you select this
setting, use the PreferredPath (on page
45 ) command to specify the path.
If you are reconfiguring a controller and do not specify a setting for this option, the existing setting remains
unchanged.
ReadCache, WriteCache
Enter a number between 0 and 100 to specify the percentage of cache that is to be allocated to drive reads
or writes. The default value for both options is 50.
The allowable cache ratios depend on the controller model and whether it has battery-backed write cache,
as described in the following table.
A "+" indicates that the specified cache ratio is allowed for that type of controller, while a "–" indicates that
the ratio is not allowed.
Read:write
ratio
RA4x00 with
16MB cache
RA4x00 with
48MB cache
All other controllers
with battery-backed
write cache
All other controllers
without battery-backed
write cache
100:0 + + + +
90:10 + + – –
80:20 + + – –
75:25 – – + –
70:30 + + – –
60:40 + + – –
50:50
+ + + –
40:60 – + – –
30:70 – + – –
25:75 – + + –
0:50*
+ – – –
0:75* – + – –
0:100 – – + –
* The cache ratio percentages do not total 100 in these cases because the additional 16-MB or 48-MB cache modules
are not used. Only the battery-backed write cache is used.
RebuildPriority, ExpandPriority
This option has three possible values: Low, Medium, and High.
SSPState
There are two settings for this option: Enable and Disable. If you do not specify a value for the SSP State, the
existing setting remains unchanged.
NOTE: The SSPState option is valid only for controllers that enable SSP on a controller basis,
such as the MSA1000 or the Smart Array Cluster Storage controllers. RA4x00 controllers support
SSP that is enabled on a logical drive basis, and use the LogicalDriveSSPState option
("
LogicalDriveSSPState " on page 45 ) instead.